Abstract: A dust core ferromagnetic powder comprises a ferromagnetic metal powder, an insulating material, and a lubricant. The insulating material comprises a phenol resin and/or a silicone resin, and the lubricant comprises at least one compound selected from the group consisting of magnesium stearate, calcium stearate, strontium stearate, and barium stearate. It is possible to achieve a dust core having high saturation magnetic flux density, low losses, and satisfactory permeability with its dependence on frequency being improved.

Abstract: A ferromagnetic powder composition for dust cores contains a ferromagnetic metal powder and 0.1-15% by volume based on the powder of titania sol and/or zirconia sol. The composition is pressure molded and desirably annealed into a dust core which exhibits a high magnetic flux density, low coercivity, low loss and high mechanical strength.

Abstract: A powder magnetic core having reduced core losses and increased mechanical strength is provided at low costs. The core is obtained by compressing a ferromagnetic metal powder and an insulating agent and then annealing the compressed body. The ferromagnetic metal powder is made up of a substantially spherical form of ferromagnetic metal particles containing Fe, Al and Si. The core has a permeability of at least 50 at 100 kHz, a core loss of up to 450 kW/m.sup.3 at 100 kHz in an applied magnetic field of 100 mT, and a core loss of up to 300 kW/m.sup.3 at 25 kHz in an applied magnetic field of 200 mT.

Abstract: A composite soft magnetic material is produced from soft magnetic metal (e.g., Sendust) particles by coating the particles with a non-magnetic metal oxide (e.g., .alpha.-alumina) in a mechano-fusion manner, or heat treating the particles to form a diffusion layer of .alpha.-alumina thereon, coating the coated particles with a high resistance soft magnetic substance (e.g., ferrite), and sintering the double coated particles under pressure as by hot pressing or plasma activated sintering. It exhibits high saturation magnetic flux density, magnetic permeability, and electric resistivity. The non-magnetic metal oxide intervening between the soft magnetic metal and the high resistance soft magnetic substance is effective in reducing core loss.

Abstract: According to the invention, a magnetic recording medium is formed by using magnetic powder having a composition of the following formula:MeO.multidot.n[Fe.sub.2-x-y-z Ga.sub.x Cr.sub.y Al.sub.z O.sub.3 ]wherein Me is at least on element selected from the group consisting of Ba, Sr, Pb, and Ca,4.5.ltoreq.n.ltoreq.6, x.gtoreq.0, y.gtoreq.0, z.gtoreq.0,x/3+y/4+z/6.gtoreq.1/6, andx/6+y/10+z/11.ltoreq.1/6,preferably the number of those particles having a particle size of from 0.5d to 1.5d being at least 65% of the entire particles wherein is an average particle size, and the Fe content on the particle surface being substantially equal to the Fe content in the particle interior, and blending the powder with a binder. Thermomagnetic recording and thermomagnetic duplication are carried out using the medium. There results a magnetic layer which has high Hc, is not easily erased once recorded, has high squareness ratio, and enables thermomagnetic recording and thermomagnetic duplication at 100.degree. to 180.degree. C.

Abstract: The invention provides a composite soft magnetic material which is prepared by coating soft magnetic metal particles with a high resistance soft magnetic substance, preferably by mechano-fusion, applying electricity to the coated particles in a mold cavity between punches serving as electrodes, for example, to thereby create a plasma, and thereafter further conducting electricity to effect plasma activated sintering. There is obtained a composite material which possesses both the high saturation magnetic flux density and high magnetic permeability characteristic of the soft magnetic metal and the high electric resistivity characteristic of the high resistance soft magnetic substance.

Abstract: Magnetic particles comprising a magnetic core and a shell covering the core are provided wherein the shell is formed from titanium nitride, titanium carbide, aluminum nitride, aluminum oxide, zirconium oxide, silicon nitride, silicon carbide, or a mixture thereof by plasma-assisted chemical vapor deposition while vibrating the core.